Measuring instrument.



w si H. L. VAN VALKENBURG.

f\ MEASURING INSTRUMENT. (-5 APPLICATION FILED SEPT. 29, 1908. j922,362, Patented May 18, 1909.

THE Nanni; Ps1-:Rs co., wAsHngarnN, n. c.

HERMON L. VAN VALKENBURG, OF NORWOOD, OHIO, ASSIGNOR TO ALLIS-CHALMERSCOM- PANY, A CORPORATION OF NEW JERSEY, AND THE BULLOCK ELECTRICMANUFACTUR- ING COMPANY, A CORPORATION OF OHIO.

MEASURING INSTRUMENT.

To all whom it may concern:

Be it known that I, HERMON L. VAN VALKENBURG, citizen of the UnitedStates, residing at Norwood, in the county of Hamilton and State ofOhio, have invented certain new and useful Im rovements in MeasuringInstruments, of which the following is a full, clear, and exactspecification.

My invention relates to measuring` instruments.

The object of my invention is to vprovide an instrument Which is verysimple in construction, sensitive, reliable, and the indicator of whichhas a long range of movement with reference to a graduated scale.

In carrying out my invention I provide a measuring instrument having anindicating means comprising a air of receptacles adapted to be filledwith air or other luid, each of which receptacles has a flexible orother yieldable diaphragm or wall and the two receptacles beingconnected together by a tube having a small bore suoli as a capillarytube so that if a movement, however `small, is given to one of thediaphragms there will be a comparatively long movement of the iluid inthe tube from one receptacle to the other, which movement can bemeasured on a suitable scale.

More speciiically considered my invention consists in an electricalmeasuring instrument comprising an electromagnetic device having a coiland an armature or core adapted to move relatively thereto, and means'lor indicating relative movement of the armature or core comprising apair of fluid iilled receptacles, connected together by a tube of smallbore, and each having a yieldable diaphragm, to one or both of which themovable member of the electromagnetic device is connected. Thereceptacle and tube may be iilled with Iiuids of two difierent colorshaving a clear and permanent line of division which serves as anindicator, or the receptacles may be illed with air and the tubeprovided with an indicator such as a small globule of mercury.

My invention further consists in the com binations and arrangements ofparts described in the specification and set forth in the appendedclaims.

For a better understanding of my invention reference is had to theaccompanying drawings in which Specification of Letters Patent.

Application led September 29, 1906.

Patented May 18, 1909.

Serial No. 336,667.

Figure 1 represents a sectional elevation of my improved measuringinstrument; and Fig. 2 is a similar view showing a slightly modifiedform of my invention.

The main features of my invention may be employed in a large variety ofmeasuring instruments, and although shown in connection with anelectrical measuring instrument, I wish it understood that in itsbroadest aspect it is not to be confined thereto.

Referring iirst to Fig. 1 oi the drawings, 1() represents anelectromagnetic device, in this case a solenoid, consisting oi' a coil11 and a movable core or armature 12. Coil 11 may be connected to anelectric circuit so that volts or amperes may be measured, or il desiredthe movable member may be also provided with a coil as is shown in Fig.2, so that watts may be measured. The core 12 is shown in position suchthat when the coil 11 is traversed by a current, the core 12 will moveinto the coil. I have provided novel and effective means 'formultiplying the movement of the core so that the value ol' the currenttraversing the coil can be mease ured on a long scale as will now bedescribed. At 13 and 13a are shown two fluid receptacles,each'consisting, in this case, oll a cupshaped or recessed member havingon one side a yieldable wall 14, in this case, a ilexible diaphragm,which is held tightly in position in some manner such as by a screwthreaded cap or ring 15. The two receptacles are spaced a suitabledistance apart and are arranged back to bach. Connecting the tworeceptacles and communicating therewith is a tube 16 oll small bore suchas a capillary tube which is transparent, being preferably made o1'glass. The electromagnetic device is located adjacent to and oppositethe diaphragm 14 o'll the receptacle 13, and the armature 12 isconnected to the diaphragm as shown at 17 so that the move ment ol' thearmature core is communicated thereto. It is seen that if the receptacleand tube are filled with a fluid that even a small movement of thediaphragm causes a comparatively long movement o'lI the fluid in thetube and ii' the tube is provided with an indicator the movement ol' thecore can easily be measured. It is also seen that such an instrument isunaffected by temperature changes if the fluid in one receptacle expandsand contracts the same as the other.

In this case I place in the receptacles and tube two liquids 18 and 18abof different colors, each liquid completely filling one receptacle and aportion of' the tube, and havmg in the tube a clear line of division 19which serves as an indicator. It is essential that the liquids in thetube do not mixor diffuse. For this reason I prefer to employ mercury asone of' the liquids. At 2O is shown a graduated scale along the tube. Ifdesired the graduations may be located on the tube. In order that theinstrument may not be affected by changes in temperature it is necessarythat the volumes of two liquids be so selected that one liquid willexpand or contract the same amount as the other, in which case the zeroposition ol the indicator will be fixed. Some means such as anadjustable screw 21 in one or both of' the receptacles may be employedfor adjusting the relative volumes of the liquids in the receptacles andtube. It is seen that when current traverses coil 11, the armature ismoved from the position shown in the drawing into the coil, whichmovement is communicated to the diaphragm 15 and receptacle 13, forcingpart of the liquid in said receptacle into the tube 16, hence moving theindicator 19 along the tube. It is seen that a long range of movementcan be given to the indicator 19 by a comparatively small movement ofthe core 12. It is also seen that the instrument is very simple inconstruction and is unaffected by changes in temperature, since theexpansion or contraction of one liquid is the same as the other.Furthermore the inertia of the liquid in the tube being so slight, theinstrument is practically dead beat.

In the modification shown in Fig. 2, the electromagnetic device 22consists of two coils, a stationary coil 23 and a movable coil 23a. Bothcoils may be connected in series in the circuit in which case the pulland relative movement are proportional to the square of the current, orof the voltage, or one of the coils may be a voltage coil and the othera current coil, so that the pull and relative movements of the'coils areproportional to the Watts. Two receptacles 24 and 24UL similar toreceptacles 13 and 13@L are employed which receptacles are spaced apartand arranged with the diaphragms 25 facing each other. The movable coil22 is mounted on a horizontally movable rod 26 and its position can beadjusted thereon by nuts 27 engaging threaded portions of the rod. Therod 26 is connected at its ends to the diaphragms 25 as is shown.Communicating with the receptacles 24 and 211a is a U-shaped capillarytube 28 having a horizontal portion 29. The rece tacles and the tube mayas in the first case he filled with different colored liquids, but inthis case I have shown a modiflcation, the receptacles and tube beingfilled with air. In the horizontal portion of the tube I provide anindicator 30 which is preferably a small globule of mercury, themovement of which can be measured on the scale 31. Thus the movement ofthe coil 22 is communicated to the diaphragms, moving one diaphragminward and the other diaphragm outward, causing a movement of the air inthe tube and hence a movement of the globule of mercury 30, the extentof which movement is proportional to the movement of the coil 22, andcan be measured on a scale 31. The instrument here shown as in the firstcase is not affected by changes of temperature.- If the mercury shouldbe accidentally moved from its zero position, means may be provided foradjusting the scale or the position of the globule for each reading.

It is evident that many changes and modifications can be made withoutdeparting from the spirit and scope of my invention. in my claims tocover all such modifications.

What I desire to secure by Letters Patent is 1. In a measuringinstrument, a pair of stationary receptacles, each having a movablewall, a tube in communication with both receptacles, the receptacles andtube being fluid filled, each receptacle containing a fluid which mayextend into the tube and which expands or contracts due to temperaturechanges the same amount as the fluid in the other receptacle, and meansfor applying force or pressure to at least one of said movable walls soas to cause a fluid movement in one direction throughout the length ofthe tube, whereby the value of said force or pressure may be measureddirectly by the extent of fluid movement in the tube.

2. In a measuring instrument, a-pair of receptacles, a connecting memberhaving a restricted passageway communicating with both receptacles, eachof the latter having a movable wall and being filled with a fluid whichextends into the tube so as to fill the same, the fluid in eachreceptacle being such that its changes in volume due to temperaturechanges are the same as the changes of the fluid in the otherreceptacle, and a movable member connected to at least one of saidmovable walls and serving when actuated to shift the correspondingmovable wall so as to cause a fluid movement in one direction throughoutthe length of the passageway, said fluid movement in the tube being ameasurable indication of the value of the force or pressure applied tothe inner wall.

3. In a measuring instrument, a receptacle having a movable wall, a tubeconnected to the receptacle, said receptacle being filled with a fluidwhich normally extends a dellnite distance into the tube, means forshifting said movable wall so as to vary the quantity of said fluid inthe tube, the extent of the fluid movement in the tube being a direct Iaim measurable indication of the Valueof the force or pressure appliedto the movable wall, and means for preventing changes in the normalvolume of said fluid in the tube due to temperature changes comprising asecond receptacle having a movable wall and connected also to said tube,said second receptacle being filled with a fluid which may extend intothe tube and which contracts or expands due to the temperature changesthe same amount as the fluid in the first named receptacle.

4. In a measuring instrument, a pair of receptacles each having amovable wall, a connecting member having a passageway which communicateswith both receptacles, a movable indicator in said passageway, theportion of the tube and the receptacle on each side of" the indicatorbeing filled with a fluid which expands or contracts due to temperaturechanges the same amount as a fluid on the opposite side of' theindicator whereby the instrument is unaffected by changes intemperature.

5. In a measuring instrument, a pair of receptacles, each having aflexible or movable wall, a tube in communication with both receptacles,said receptacles and tube being fluid filled, the fluid in eachreceptacle being such that it expands and contracts due to temperaturechanges substantially the same amount as the fluid in the otherreceptacle, means for causing` a shifting of the flexible or movablewalls of the receptacles, said tube containing an indicator whereby thefluid movement may be measured in the tube.

6. In a measuring instrument, a pair of receptacles, each having aflexible or movable wall, a tube in communication with both receptacles,said receptacles and tube being fluid lled, the fluid in each receptaclebeing such that it expands and contracts due to temperature changessubstantially the same amount as the fluid in the other receptacle, amovable actuating member connected to the movable wall of one of saidreceptacles, said tube containing an indicator whereby the fluidmovement may be measured in the tube.

7 In a measuring instrument, a pair of receptacles, each having aflexible or movable wall, a tube in communication with both receptacles,said receptacles and tube being fluid filled, the fluid in eachreceptacle being such that it expands and contracts due to temperaturechanges substantially the same amount as the fluid in the otherreceptacle, and means whereby force or pressure may be applied to one ofsaid movable walls thereby causing a fluid movement in the receptaclesand tube, said tube containing an indicator whereby the fluid movementmay be measured in the tube.

8. In an electrical measuring instrument, an electro-magnetic deviceincluding a movable member, a pair of receptacles, each having aflexible or movable wall to at least one of which the movable member isconnected, a tube in communication with said receptacles, saidreceptacles and tube being fluid filled, the fluid in each receptaclebeing such that its contraction or expansion due to temperature changessubstantially balances that of the fluid in the other receptacle, saidtube containing an indicator whereby the fluid movement may be measuredin the tube.

9. In an electrical measuring instrument, an electro-magnetic'devicecomprising a movable member, a pair of receptacles each having aflexible diaphragm to at least one of which the movable member isconnected, a tube in communication with both receptacles, saidreceptacles and tube being fluid filled, said tube having a movableindicator and a scale along said tube, the changes in volume of thefluid on one side of the indicator due to temperature changes beingsubstantially the same as the changes in volume of the fluid on theopposite side of the indicator, whereby the zero position ofthe'indicator is constant for all temperatures.

10. In a measuring instrument, an indicating device comprising a pair ofreceptacles, each having a movable wall, a connecting member having arestricted passageway communicating with both of said receptacles, saidreceptacles and comiecting member being fluid filled and said memberhaving an indicator adapted to be shifted by fluid movement in saidpassageway, the volume and coefficient of expansion of the fluid on eachside of the indicator being such that the zero position of the indicatoris substantially constant for all temperatures.

In testimony whereof I affix my signature, in the presence of twowitnesses.

IIERMON Il. VAN VALKENBURG.

Witnesses:

ARTHUR F. Kwis, FRED J. KiNsEY.

